Evaluating integrals with sigma notation Ask Question Asked 13 years, 1 month ago Modified 8 years, 1 month ago

In school, we just started learning about trigonometry, and I was wondering: is there a way to find the sine, cosine, tangent, cosecant, secant, and cotangent of a single angle without using a …

Mar 24, 2017 · A lot of questions say "use polar coordinates" to calculate limits when they approach 0 0. But is using polar coordinates the best way to evaluate limits, moreover, prove …

I'm supposed to calculate: $$\\lim_{n\\to\\infty} e^{-n} \\sum_{k=0}^{n} \\frac{n^k}{k!}$$ By using WolframAlpha, I might guess that the limit is $\\frac{1}{2 ...

How would you evaluate the following series? $$\\lim_{n\\to\\infty} \\sum_{k=1}^{n^2} \\frac{n}{n^2+k^2} $$ Thanks.

Apr 24, 2017 · Evaluate the contour integral ∫C z+1 z2−2zdz using Cauchy's residue theorem, where C is the circle |z| = 3. I see that the function has 2 singularities, at 0 and 2, so I need to …

As x gets close to 3, the numerator is getting close to −1 and the denominator is getting close to 0. Something nonzero (rather, not tiny-approaching-zero) divided by something tiny-approaching …

Oct 20, 2017 · Show that det(A) = 0 det (A) = 0 without directly evaluating the determinant Ask Question Asked 7 years, 7 months ago Modified 7 years, 7 months ago

@Cruncher: To evaluate such a limit by L'Hôpital, you need to know that d dx x−−√ = 1/(2 x−−√), and to prove that formula correct (from the definition of derivative), you need to be able to …

While working on some probability question, I had to evaluate limx→∞ arctan(x) lim x → ∞ arctan (x). I knew the answer intuitively as π/2 π / 2, yet I cannot figure out how to prove it by …